Hydraulic transmission



March s. v. E. TAYLOR- 37 44 HYDRAULIC TRANSMISSION Fil ed D50, 1, 1943 2 Sheets-Sheet 1 26 I 27 9 34 2s IO INVENTOR SCOTT V.E.TAYLOR- ATTORNEY s. v. E. TAYLOR 2,437,448

HYDRAULIC TRANSMISSION Filed Dec. '1, 1945 2 Sheets-Sheet 2 INVENTOR 6| SGOTTVETAYLOR ATTORNEY Patented Mar. 9, 1948 UNITED STATES PATENT OFFICE 2,437,448 mmmcmansmssron v Scott v. a. Taylor, Cleveland, Ohio application December 1, 194:, Serial No. 51am- 18 mm. (c1. 192-61) My invention relates to hydraulic transmisq sions and more particularly to one of the jet reaction type, said invention having for its general object to improve the hydraulic transmission disclosed in my Reissue Patent'No. 20,988, issued January 24,1939.

A more specific object of my invention'is to produce a hydraulic transmission of the type referred to in which a more compact and emcient relacasing.

shaft and the cup-shaped casing. The stub shaft has a splined portion II which cooperates with internal splines it on a flange ll extending inwardly, from the closed end of the cup-shaped Roller bearings II are provided between section 9 and the stub shaftand a "Welsh" H is provided to seal the end of the stub shaft beyond the splines. The other end section In of driven shaft. The stub shaft II is formed as an aerefor to maintain a constant pressure in said assage.

Further objects of my invention are to produce hydraulic transmission which is simple in con- ;ruction and arrangement of parts, readily asambled and economically manufactured and one hich has an increased torque over prior hyraulic transmissions per-ating under similar veeds.

Other objects of my invention will become 'ap- Trent from the following description taken in nnection with the accompanying drawings in aich Figure 1 is a vertical sectional view of a hythe rotor is provided with a bore It for receiving the inner end of driven shaft 2, a portion of said bore having splines I! for cooperation with splines I 8 on the driven shaft, thus providing a driving connection between the rotor and the integral extension from one side of a gear l9 and the otherslde of this gear is also provided with an integral stub shaft extension which extends into bore l6 of end section in of the rotor, a roller bearing 2| being provided between the shaft and section. The end section ii! is provided with an annular flange 22 which is journaled in closure plate 5 by means of a bearing 23. A portion of the closure plate closely surrounds driven shaft 2 and carries an "-ring seal 24 to prevent any leakage of fluid from the interior of easing 4.

Three like irregularly-shaped sections 25 and wear plates 28 and 21 are provided between the v end sections 9 and it) of rotor 8, wear plate 26 being interposed between section 9 and sections 25 and wear plate 21 between section III and sections 25. The thickness of each section 25 is the same as the width of gear l9 and the wear plates fit closely against the end surfaces of gear l9 to provide a seal for the gear. Sections 25, wear 'aullc transmission embodying my invention;

gure 2 is a sectional view taken on the line 2-2 'Figure 1; and Figure 3 is a view of a modified lve mounting. Referring to the drawings in detail, numeral I iicates the driving shaft of the transmission d 2 the driven shaft thereof. The driving aft, which is driven by a prime mover has a p-shaped casing 4 connected thereto by means bolts 3, said casing being closed at its open :1 by a closure plate 5 which is secured to a age 6 by means of suitable fastening studs and ts 1. Within the cup-shaped casingis a rotor lerally indicated by the numeral 8, this rotor ng spaced from casing I and connected for ro- [on with the driven shaft 2. The rotor has end tions 9 and Ill, section 9 being mounted for re,- ion on astub shaft II. This stub shaft is in 9.1 alignment with the driving shaft and conted thereto inorder to be rotatable with the plates 26 and 21, and the end sections 9 and ID of the rotor are all held in assembled relation by three sets of bolts 28, 29, and 30 of diii'erent sizes, each set .of bolts passing through a section 25 as I best shown in Figure 2. The heads of the bolts are inset in end section 9 and the nuts therefor are inset in vend section I II in order projections on the rotor.

I Sections 25 are so shaped that when mounted between sections 9 and I II in circumferential relation they form three passages 2| leading outwardly from gear I! and opening into the perioh to eliminate cry of the rotor in a general tangential direction as shown. The inner edges of each section have a curved surface 32 in the form of a segment of a cylinder and together these cylindrical surfaces form a chamber 33 within which gear I! rotates.

The cylindrical surface cooperates with the end surfaces of teeth IQ of the gear to form a seal. Each section 25 is also shaped to form a substantially closed cylindrical chamber 3|, the three chambers being meshing area of the gears.

' lindrical chamber 34 and 3 spaced, 120 about the axis of gear l9. ,Closely fitted within a spinner 35 in the form of a gear, the teeth 35'. of which mesh with thejteeth and gears 35, together with sections 25, provide three gear pumps. each of which, is capable of forcing fluid into the inlet end 35 of passage 3|, which inlet is arranged to be closely adlacent the Each section also has a drilled passage 31 which intersects the c enters chamber 33 in which gear l9 rotates. Each passage 3! permits liquid to flow from the exterior of the rotor to a pump at a point adjacent the meshing area of the gears but ya the side opposite the inlet end 35 for the exhaust passage 3|.

Each of the passages 3i forming the exhaust passages for the pumps is arranged to be of the converging type, that is, they converge toward the outlet end 39 which empties into the space between the rotor and the external casing 4 in a general tangential direction as already noted. Since this exhaust passage has its outlet at the periphery of the rotor, the force resulting from the exhaust fluid will thus have an operating arm substantially greater than the pitch radius of thedriving gear l9. Associated with each outlet end of passage 3| is a valve otally mounted in a section 25 by means of a cylindrical portion 40 received in a cylindrical socket 4i. A yieldable filler material 43 is provided in the space between passage surface 42- of the valve element and the portion of section 25 adjacent the pivot joint of the valve element, said filler material being secured to the section and the valve element as by binding, This material provides a smooth wall for the outlet port of passage 3| and yet permits the valve element to pivot and control the extent of opening of the outlet end 38; The surface 42 of the valve element. the yieldable filler material 43, and the converging relation of the walls of passage 3i are so arranged that when the valve is fully open, passage 3! has a cross-section shape similar to a Venturi tube and when the valve is almost closed, the cross-section shape of the outlet end is similar to that of a converging type fire hose nozzle with an included angle, for example, as of 13 degrees, 24 minutes. I I

Each valve element 39 is adapted to be acted upon by two springs 44 and 45 which normally apply forces moving the valve element to closed position, thus preventing flow of liquid out of passage 3i. The spring 44 is positioned in a bore 46 extend'ng through section 9 of the rotor and spring 45 is positioned in a bor 41 in section III of the vrotor. The outer ends of the bores in which the springs lie open into a rectangular slot 48 which extends axially across the rotor being formed by cut-outs in sections 9 and I0, wear plates 25 and 21, and each section 25. Each slot receives a rectangular bar 49 which is interposed between the ends of springs 44 and 45 and the outer curved end of valve element 39, thus providing means whereby the springs can apply the valve element which lies between The end of each spring the valve element is held in its bore by a screw pin 50; When the transmission is not in operation, the springs will act on the valve elements to hold them in closed positions, thus closing the passages 3|. All the springs are alike and are designed so that each pair will apply a predetermined closing force to each valve element,

each chamber 54 is ofgear l9." Gear is element 39 piv- V Figures 1 and 2.

Each gear 35 is oppodte sides of the gear, the shafts being secured to the gear by being pressed into the bore thereof. The end portion 53 of 54 of shaft 52, which extend from opposite sidesof the gear, are enlarged. as best shown in Figure 1. The portion 53 is iournaled in the end section 9 by roller bearings 55 and portion 54 is mounted in the end section III of the rotor by roller bearings 55. Shaft 5| is formed with a flange portion 51 for cooperation with the outer surface of wear plate 25 and shaft 52 has a flange portion 59 for cooperation with the outer surface of wear plate 21. These flanges in cooperation with the wear plates provide extra sealing means for gear 35 and chamber 34 thereof. A double sealing arrangement is provided by the end surfaces of the gear engaglngthe inner surfaces of the wear plates and the flanges engaging the outer surfaces of the wear plates. Pins 59 are provided for holding the roller bearings 58 of shaft 52 in position.

The casing 4 is adapted to be filled with a suitable liquid to any desired level line such as that indicated at "L" and to accomplish this, a filler pipe 50 is provided which is closed by a cap 50'. This pipe is so arranged that when all possible liquid is put into the casing through the pipe, the level line will be at the proper height. The external surface of easing 4 is also provided with suitable fins iii in order to facilitate a rapid dissipation of heat during operation of the transmission.

The operation of my improved hydraulic transmission is as follows: The driving shaft is rotated in the direction indicated by the arrow A in Since both gear l9 and easing 4 are connected to the driving shaft, their direction 'of rotation will be the same as that of the driving shaft. With gear l9 rotating in the counter-clockwise direction as viewed in Figure 2, gears 35 will be driven in a clockwise direction as seen in the same figure. Rotation of the gears will cause the three pumps to operate and each pump will cause liquid under pressure to be developed in a passage 3| which will be forced through the outlet end 38 into the space between casing 4 and the rotor. In order to be forced out of passages 3|, the liquid must 39 against the action of springs 44 and 45. Since valves 39 tend to close passages 3|, it is seen that a load will be imposed upon the gears and consequently, the rotor will be caused to rotate in the direction indicated by the arrow 0" and gears 35 will rotate about the axes of the driving and driven shafts of gear I9. With rotation of the rotor, the driven shaft 2 will be rotated. If there is a load on the driven shaft, it will also be applied to the rotor and tend to prevent rotation thereof. This load causes gears 35 to be rotated about their own axes by gear iii to bring about the pumping operation for developing liquid pressure in passages; l

As already noted, springs 44 and 45 apply a substantially constant force to each valve element 39 to bias it toward closed position. The valves are so arranged that the liquid pressure in passage 3i will act against the closing force of the springs. Thus these springs working through the valves will tend to maintain a substantially constant liquid pressure in passages 3|, when the load on the driven shaft is large, the rotor and, therefore, the planet gears will be held against rotation about the axis of gear I9 provided with two mounting shafts 5| and 52 which extend from shaft 5i and the end portion open valve ass-2344s butcanberotatedabouttheir ownaxesagainst theloadimposedbythevalveelement. 'I'hevolumeofiiuidbeingpumpedwillbelarsaandforthisvohimetobeexhaustedthevalveltwill be opened against the constant spring force.

The liquid pressurein passage 3|, however. will remain substantially constant. As the load on the driven shaft decreases. the constant liquid pressure maintained in pe 3| will cause the rotor to increase in speed and the difference of speed between the driving shaft and driven shaft will decrease. With this decrease in difference in speed, the rate of rotation of the planet gears about the axis of gear I! will increase andthe rate of rotation about their own axes will decrease. As a result a less volume of fluid will be pumped and the valves will be closed farther lmder the action of the springs. As the load further decreases on the driven shaft, the speed of the rotor will further increase with a resultant decrease in the puumping action of the pumps and further closing of valve elements 39. There will be further decrease of rate' of rotation of the planet gears about their own axes as the load on the driven shaft decreases further until the diiference in rotation between the rotor and the driving shaft is small and the speed ratio between the shafts is substantially 1 to 1 or direct drive. At this time there will be a little pumping action by the gears as the load imposed on the planet gears by the valves prevents their rotation about their own axes. The torque being transmitted to pick up the load on the driven shaft is accomplished by the gear thrust action between the sun gear and the planet gears and the jet reaction of the liquid being exhausted through passage 3| which has a particular contour so that it is exhausted in a general tangential direction as previously noted. Thesum oi the two forces. that is, the forces resulting from the gear thrust action and the jet reaction multiplied by their respective arms about the axis of the rotor divided by the torque input gives the torque multiplication. Due to thefact that the jet reaction is acting through an arm substantially greater than the pitch radius of the driving gear I! there will be a substantial increase in torque output over an arrangement where there is no jet reaction or it acts through an arm less than the pitch radius of the driving gear.

From the foregoing it is seen that the hydraulic transmisison operates automatically to give infinite speed ratios between the driving and driven shafts. -As the torque necessary to move the load decreases, the diiference in speed between the driving and driven shafts decreases. Every- 7 thing about the transmission is automatic. and

thetorque transmitted will'be at the ratio re- 5 quired for the load. The torque input, however,

remains substantially constant regardless of differences in speedsbetween the driving and driven shafts.

It is to be noted that the entire construction of the transmission is very simple as the rotor is comprised essentially of only two end sections and three inner sections. The chambers for the gears of the pumps are formed by the wear plates and the three like central sections which are so irregularly-shaped that when properly positioned they form the chamber for the central gear, the chambers for the planet gears, and the exhaust 16- be accurately to give the proper application force. The outer casing l. which rotates the driven shaft. is spaced from the rotor,

tlluscausing a considerable decreasein anyskin friction resulting from the contact of theliquid with the surface of the rotor and the casing. The pumps are of very simple construction 'requiring only a single sun gear and three planet sears. They are all embodied within the rotor, thus streamlining the exterior thereof in order to decrease hydraulic friction.

It may be desirable to provide suitable scoopsto insure that suiiicient liquid enters the intake passages for the pumps under all conditions. This can be accomplished by means of the specially.

designed coop .ilshown in Figure 2. These scoops are arranged so that they will pick up liquid in either direction and direct the liquid toward the intake 31. When there is a large load the driven shaft, the driving shaft will be rotating at a greater speed than the driven shaft and consequently it will tend to carrythe liquid which is in the space between the casing and th rotor in. the direction of rotation of the casing. Under these conditions portion '3 of the scoop which opens toward the rotating liquid will direct liquid intothe intake passages. When ,the .casipgsaadjrotor are rotatingat similar the inertia of the liquid may be such that it will not move as rapidly as the rotor and the casing so that liquid can enter the scoop portion 83. However,

the other scoop portion which opens in the opposite direction will pick up sumcient liquid to keep the intake passage 31 supplied, The liq-' uid being exhausted to passages 3| will also have an eil'ect upon the relative movements of the liquid with respect to the rotor and casing, Howbearing mounting in openings 68 and 61 0f the wear plates. By. means of this arrangement the yieldable material can be eliminated and the contour of the valve element arranged to be continuous' with the contour of section 25 at the pivoted end of the element and thus provide a smooth wall at the outlet end of passage 3 I.

Being aware of the possibility of modifications in the particular structure herein described without departing from the fundamental principles of my invention, I do not intend that its scope be limited except as set forth by the appended claims.

Having fully described my invention, what I claim as new and desire to secure by Letters Patent of the United States is:

1. In a hydraulic transmission, a driving memher, a driven member, a rotor connected to the passages for the pumps, The valves are of sim-' ple construction and are directly operated upon by springs which are of the coil type and can driven member, a gear pump. associated with the rotor and comprising meshing gears journaled in the rotor and positioned within the outlines thereof, one of said gears constituting adrlving g'ear having an axis coinciding with the rotor' axis, means for driving one of the gears from the driving member, said rotor being provided with an inlet passage from the exterior of the rotor As shown, the valve eleconnected to the driving and type of flow as curvature pump associated with ing with the axis of the rotor passage from the and capable of to a radial line of the rotor so chosen that the reaction force produced by the discharged liquid will act on the rotor at a distance from its axis substantially greater than the pitch radius or the drivin gear, and automatically Op rable means for maintaining a substantially constant liquid pressure in the exhaust passage.

2. In a hydraulic ber, a driven member, a

member to rotate therewith, a rotor in the casing spaced a substantial distance from the walls thereof and connected to the driven member, a chamber in.the rotor, a spinner in the chamber iournaled in the rotor, means for supplying liquid to the spinner chamsmooth curved passa e so arranged and extending to the exterior of the rotor at an angle to a radial line as to produce a reaction force on the rotor-actin at a substantial distance from the axis of the rotor and in a direction to aid in the rotation of the rotor, means for driving the spinner from the driving member to thereby cause the spinner to force fluid out of the exhaust passage, and spring-biased valve means for automatically controlling the extent oi opening of the exhaust assage to maintain substantially uniform liquid pressure therein driven members and being so associated with the open end of the exhaust passage as to cause no substantial change in direction of flow or fluid as it passes to the exterior of the rotor other than as determined by the curvature of the exhaust passage.

3. In a hydraulic transmission, a driving member, a driven member, a rotor connected to the driven member, pump means associated with the rotor, means for driving the pump means by the driving member, a liquid supply, means for connecting the supply to the pump intake, means providing a smooth walled exhaust passage in the rotor from the pump to the exterior of the rotor, said exhaust passage being so shaped as to cause pumped liquid to converge toward its outlet end and arranged and curved as to discharge liquid from the rotor in a, eneral tangential direction and opposite the direction of rotation of the rotor to thus produce a reaction force on the rotor acting at a substantial distance from its axis and in a direction to aid in the rotation of the rotor, and spring-loaded valve means for maintainin the liquid in the exhaust passage under pressure without any substantial change in its direction determined by the shape and of the exhaust passage, said spring of the valve acting on the valve with such uniform force as to automatically maintain the input torque substantially constant at all discharge rates of the liquid.

4. In a hydraulic transmission, a driving member, a driven member, a rotor connected to the driven member, a casing surrounding the rotor in spaced relation and containing liquid, a gear the rotor and comprising a gear mounted for rotation on an axis coincidand a second gear meshing with the first gear and mounted for rotation in.the rotor on an axis eccentric to the rotor axis, means providing an the pump from the space between the rotor and easing, means providing an exhaust passage from thepump to the exterior of the rotor and capable at all speeds oi the inlet passage to bars for the gears,

the chambers 01 the gears in such manner as it' haust passage and maintaining pumped liquid pressure therein at a substantially constant value.

5. In a hydraulic transmis ion, a driving member, a driven member, a rotor connected to the driven member, a gear journaled in the rotor and having its axis coinciding with the axis or said rotor, a second gear iournaled in the rotor and meshing with the first gear, said rotor and gears being so arranged as to provide cylindrical chammeans for supplying liquid to will be placed under pressure by the rotation of the gears, means providing an exhaust passage for the liquid pressure, and spring-biased valve means for maintaining the liquid in the exhaust passage under a substantiallfconstant pressure. said exhaust passage being so arranged as to discharge liquid from. the rotor in a general tangential direction and away from the direction of rotation of the rotor and the perpendicular distance between the rotor axis being substantially greater than the pitch diameter of the first gear.

6. In a hydraulic transmission, a driving member, a driven member, a liquid containing casing connected to the driving member, a rotor in the casing spaced from the walls thereof and connected to the driven member, a chamber in the rotor, a spinner in the chamber journaled in the rotor, means for supplying liquid to the spinner chamber and for exhausting it therefrom through a passage extending to the exterior or the rotor, means for driving the spinner from the driving member to thereby cause the spinner to force liquid out oi the exhaust passage, and spring-biased valve means for controlling the exhaust passage, said exhaust passage being so arranged as to discharge liquid from the rotor in a general tangential direction and having smooth curved walls and being so constructed to cause the liquid flowing therethrough to converge toward the outlet end.

, connected to the driving member,

7. In a hydraulic transmission, a driving member, a driven member, a liquid containing casing a rotor in the casing spaced from the walls thereof and connected to the driven member, a chamber in the rotor, a spinner in the chamber journaled in the rotor, means for supplying liquid to the spinner chamber and for exhausting it therefrom through a passage extending to the exterior of the rotor,

means for driving the spinner from the driving member to thereby cause the spinner to force liquid out or the exhaust passage, and a springbiased valve element for controlling the exhaust passage, said exhaust passage being so arranged as to discharge liquid from the rotor in a general tangential direction and having smooth curved walls and being so constructed to cause the liquid flowing therethrough to converge toward the outlet end and said valve element being so constructed that it will form a portion of the wall of the converging passage when substantially closed and when openwill cause the passage to diverge at its discharge end.

8. In a hydraulic transmission, a driving member, a driven member, a rotor connected to the driven member, pumping means the said tangential direction and associated with the rotor, means for driving the pumping means by the driving member. a liquid supply connectedto the inlet or the pump, means providing an exhaust passage in the rotor from the pump anddischarging to the exterior or the rotor, and a pring-biased pivoted valve element associated with the exhaust passage, said exhaust passage converging toward the discharge end and said valve element being. so formed and associated with the passage that when closed there, results a continued convergence of the exhaust passage and when fully opened there results a gradual divergence 01' the exhaust passage following convergence. Y

9. In a hydraulic transmission, a driving member, a driven member, a rotor connected to the driven member, pumping means associated with the rotor, means for driving the pumping means by the driving member, a, liquid supply connected to the inlet of the pump,- means providing a curved passage in the rotor from the pump and discharging to the exterior of the rotor in a general tangential direction opposite that of the direction of rotation oi'the rotor, and a springbiased pivoted valve element associated with'the exhaust passage, said exhaust passage conver ing toward the discharge end and said valve element being so formed and associated with the passage that when closed there results acontinued convergence of the exhaust passage and when fully opened there results a gradual di-- vergence of the exhaust passage following convergence.

.10. In a hydraulic transmission, a driving member, an axially-aligned driven member, a rotor connected to thedriven member, said rotor comprising end sections and separate irregularly shaped central sections secured together, said central sections being so shaped and associated with each other when mounted between the end sections as to provide a central chamber, radially-positioned cylindrical chambers communieating with the central chamber and curved exhaust passages of a width equal to the thickness ofv the central sections and leading from the central chamber to the exterior of the rotor at a general tangential direction to its surface, a gear mounted in the central chamber and connected to be driven by the driving member, a gear in each cylindrical chamber and meshing with the first named gear, means for providin an inlet passage from the exterior or the rotor to each cylindrical chamber, and a spring-biased valve means for controlling each exhaust passage and being so arranged and associated therewith as not to substantially modify in all operative posi- 'tions the direction of flow of liquid as determined by the curvature of said exhaust passage and at the same time so automatically control the passage as to insure a smooth torque output reand passages between sections leading from the central chamber to the exterior or the rotor, a gear mounted in the central chamber and connected to be driven by the driving member, a gear in each cylindrical chamber and meshing with the first named gear, means for providing an inlet passage from the exterior of the rotor to each cylindrical chamber, a pivoted valve for controlling each exhaust passage, and a coil spring mounted in each end section and connected to apply a substantially constant force for biasing each valve toward closed position. v

12, In a hydraulic transmission, a driving member, an axially-aligned driven member, a rotor connected to the driven member, said rotor comprising end sectionsand a central section,

. said central sectionbeing arranged to provide a cylindrical chamber, an inlet passage to the chamber and an exhaust passage therefrom, a

gear iournaled in the rotor and having its axis coincidin with the axes of the driving and driven members, a gear positioned in the cylindrical chamber and meshing with the first named gear, stub shafts connected to and extending iromoppositesides'of the last named gears, said shafts having enlarged outer ends journaled in the end sections of the rotor,,a plate between each end section and the central section for sealing coop eration with the and surfaces of the gears and with said enlarged outer ends of the stub shafts, and spring-biased valvemeans for controlling the exhaust passage.-

sulting from gear-thrust action and jet reaction of the liquid.

'11. In a hydraulic transmission, s. driving member,-an axially-aligned driven member, a cylindrical casing connected to be driven by the driving member, a rotor-connected to the driven member and positioned in the casing in spaced relation to the walls thereof, said rotor comprising end sections and a plurality of independent irregularly shaped central sections secured together, said central sections being so shaped and associated with each other when mounted between the end sections as to provide a central chamber, radially-positioned cylindrical chambers communicating with the central chamber 13. In a hydraulic transmission, a driving member, a driven member, a rotor connected to the driven member, a pump positioned in the rotor, said rotor being provided with an inlet passage from the exterior of the rotor and an exhaust passage extending to the exterior of the rotor, a valve pivotally mounted to the rotor and associated with the exhaust passage to control the area or the discharge end or the exhaust passage, springs positioned in said'rotor on opposite sides of the valve, anda bar extending between the ends of the springs and adaptedto transfer force from the springs to the valve to bias it 'to closed position.

14. In a hydraulic transmission, a driving member, a driven member, a rotor connected to the driven member and comprising a central section and end sections, a pump positioned in the central section of the rotor, said central section of the rotor being provided with an inlet passage from the exterior of the rotor and an exhaust passage extending to the exterior of the rotor, a pivoted valve associated with the exhaust passage to control the area of the discharge end of the exhaust passage, coil springs positioned in the end sections of said rotor on oppmite sides of the valve, and abar extending between the ends of the springs and adapted to transfer, force, from the springs to the valve to bias it to closed posit on i 15. In a hydraulic transmission, member, a driven member, a liquid containing cylindrical casing connected to the driving shalt,

a rotor positioned in the casing in spaced relation from its-walls and connected to the driven member, pump means positioned within the rotor and driven by the driving member, said rotor being provided with an inlet passage from the exterior or the rotor to the pump and an exhaust passage from the pump to the exterior or the rotor, a double scoop means carried: by the rotor and arranged for directing liquid from the space between therotor an easing wall into the adriv'lng rapidly than a rotor axis and haust passage leading from 11 I when the rotor is moving more the liquid in the same direction or the liquid is moving more rapidly than the rotor in the same direction. and a spring-biased valve for controlling the exhaust passage.

16. In a hydraulic transmission, a driving member, a driven member, a liquid containing casing, a rotor in the casing connected to the driven member, a pump carried by the rotor, gearing means for driving the pump including a driving gear having an axis coinciding with the connected to the driving member, means for supplying liquid to the pump, an .ex-

tending to the periphery oi haust passage between thepump and rior oi the rotor being inadirectionatanangletoaradiallineand in'a direction opposite the rotation or the rotor so as to produce a reaction iorce on the rotor acting at a distance from the axis 01, the rotor and which distance is substantially greater than the pitch radius or the driving gear, and spring the rotor, said exthe extecurvedsoastodischargethe pump and ex- 12 adjacent the outlet end of for main taming D p liqat a substantially constant biased valve means the exhaust e uid pressure therein value.

SCOTT V. E. TAYLOR.

nmmmcns crrnn The following references are of record in the the of this patent:

UNITED STATES PATENTS Number Name 7 Date 1,283,711 Everett Nov, 5, 1918 1,354,228 Thompson. Sept. 28, 1920 1,752,385 Johnson Apr. 1, 1930 1,954,418 Ley Apr. 10, 1934 2,066,450 Bascle et a1 Jan. 5, 1937 2,818,028 Thomas May 4, 1943 2,371,227 Dodge Mar. 13, 1945 FOREIGN PATENTS Number Country Date 417,017 Great Britain Sept. 26, 1934 

